While the moon was out for my early morning trip, there were also high thin clouds cutting down on the light. The weather map showed some sort of storminess to the east which we'd somehow missed. But was calm (and mosquitoes out!) so was easy to hear first Oblong and then Castle finally have an eruption. That was the first in about 30 hours, and for the first ten minutes ago it acted like it was going to be another minor. The sound would completely cease for about 5 seconds, then Castle would have another noisy surge.
One thing I hadn't had so far this trip was a short nighttime Grand wait. Being out there for 3 or 4 hours is not only tiring, but usually means that I don't get as much sleep as I probably need. (Yes, sitting in the cold takes effort.). So it was a bit of a relief that I only had to wait two Turban intervals for this early morning's one burst eruption.
There was a plane circling the area, waiting for an Old Faithful eruption. At the same time, Grand began to show signs that it might erupt. As Old Faithful started, I mentioned that I hoped that Grand might hold off long enough that they'd see Grand in the rear-view mirrors (if any). And that's exactly what happened. As the plane disappeared to the north, the several minutes of waves finally resulted in Vent beginning to overflow. And given that Grand had a two burst eruption, it was an all-around nice eruption.
I really need to remember that I do have a camera with me. Otherwise I'd have a picture of the bison that walked within 20 feet of the boardwalk right after the Grand eruption. It proceeded on directly toward West Triplet, only changing course when it encounter the steam from the eruption and the water. It showed a bit of agitation from that encounter, then calmly continued on toward Spasmodic.
On the walk back, saw an eruption of Tilt for the first time this trip. (That's "Tilt Geyser", not "Tilt's Baby", by the way). Have seen the vent empty several times, so it might be fairly frequent, on the order of several times per day.
In the evening it seemed unlikely that Grand would erupt before sunset. Turns out that right about sunset West Triplet started. After that, when there still would have been quite a bit of light, there was a delay and so Grand waited two more Turban eruptions and ended up erupting just before any light was gone completely. A second burst, if it had happened, would have been hard to see.